Dolphin Olbia: real or fake?

Hi, I have this ancient coin (32 mm) and I would know if it's real or maybe fake. Is there any way for see if it is authentic?
Unfortunately I don't know the weight :/
Can anyone help me?
Thanks in advance.
Nicola

Very blurry picture so it's hard to figure out anything about it but it does look like it's been casted.

Many fakes for this "coinage" and the rough characteristic of it doesn't help us. Almost impossible to be fixed on the authenticity...